(1.21) Here is a stemplot of the average travel times to work for workers in the 50 states and the District of Columbia who are at least 16 years of age and don't work at home. The stems are whole minutes and the leaves are tenths of a minute.

15	67
16
17	6779
18	26
19
20	056788
21	38
22	12334799
23	357889
24	01268
25	0012569
26	689
27	29
28
29	13
30	78

The center of the distribution is close to minutes.

(Give your answer as a exact number.)